638 research outputs found
Secure Full-Duplex Two-Way Relaying for SWIPT
This letter studies bi-directional secure information exchange in a
simultaneous wireless information and power transfer (SWIPT) system enabled by
a full-duplex (FD) multiple-input multiple-output (MIMO) amplify-and-forward
(AF) relay. The AF relay injects artificial noise (AN) in order to confuse the
eavesdropper. Specifically, we assume a zeroforcing (ZF) solution constraint to
eliminate the residual self-interference (RSI). As a consequence, we address
the optimal joint design of the ZF matrix and the AN covariance matrix at the
relay node as well as the transmit power at the sources. We propose an
alternating algorithm utilizing semi-definite programming (SDP) technique and
one-dimensional searching to achieve the optimal solution. Simulation results
are provided to demonstrate the effectiveness of the proposed algorithm.Comment: Submitted to IEEE Wireless Communications Letter
Edge and Central Cloud Computing: A Perfect Pairing for High Energy Efficiency and Low-latency
In this paper, we study the coexistence and synergy between edge and central
cloud computing in a heterogeneous cellular network (HetNet), which contains a
multi-antenna macro base station (MBS), multiple multi-antenna small base
stations (SBSs) and multiple single-antenna user equipment (UEs). The SBSs are
empowered by edge clouds offering limited computing services for UEs, whereas
the MBS provides high-performance central cloud computing services to UEs via a
restricted multiple-input multiple-output (MIMO) backhaul to their associated
SBSs. With processing latency constraints at the central and edge networks, we
aim to minimize the system energy consumption used for task offloading and
computation. The problem is formulated by jointly optimizing the cloud
selection, the UEs' transmit powers, the SBSs' receive beamformers, and the
SBSs' transmit covariance matrices, which is {a mixed-integer and non-convex
optimization problem}. Based on methods such as decomposition approach and
successive pseudoconvex approach, a tractable solution is proposed via an
iterative algorithm. The simulation results show that our proposed solution can
achieve great performance gain over conventional schemes using edge or central
cloud alone. Also, with large-scale antennas at the MBS, the massive MIMO
backhaul can significantly reduce the complexity of the proposed algorithm and
obtain even better performance.Comment: Accepted in IEEE Transactions on Wireless Communication
Does the Dirac Cone Exist in Silicene on Metal Substrates?
Absence of the Dirac cone due to a strong band hybridization is revealed to
be a common feature for epitaxial silicene on metal substrates according to our
first-principles calculations for silicene on Ir, Cu, Mg, Au, Pt, Al, and Ag
substrates. The destroyed Dirac cone of silicene, however, can be effectively
restored with linear or parabolic dispersion by intercalating alkali metal
atoms between silicene and the metal substrates, offering an opportunity to
study the intriguing properties of silicene without further transfer of
silicene from the metal substrates
MiR-541-3p suppresses gastric cancer via negative regulation of HSF1
Purpose: To explore the effects of miR-541-3P on the expression of heat shock transcription factor 1 (HSF1) in gastric cancer cells (GC).Methods: The MicroRNA Target Prediction Database was used to predict whether miR-541-3p interacts with HSF1. Interaction was assessed by dual-luciferase reporter assays. Furthermore, miR-541-3p mRNA levels in GC cell lines were determined by qRT-PCR. Human GC cell lines MKN45 and NCI-N87 were transfected with miR-541-3p mimic. Cell apoptosis, proliferation, invasion, and migration were evaluated using flow cytometry, apoptosis assays, Edu assays, CCK-8 assays, and transwell assays, respectively. Caspase-3, Bcl-2, and cleaved caspase-3 expression levels were determined by western blot.Results: Expression of miR-541-3p was significantly down-regulated in GC cells. Functionally, miR-541-3p mimic inhibited GC cell proliferation, migration, and invasion and induced apoptosis in vitro (p <0.01). Mechanistically, miR-541-3p interacted with HSF1 and inhibited its expression. Overexpression of HSF1 counteracted the effects of miR-541-3p mimic in GC cells.Conclusion: These results indicate that miR-541-3p suppresses the development of GC by targeting HSF1 and thus, is a possible strategy for for the management of GC
- …